Roof membrane

[wooju]

Hello all, 
I bought a house few years ago and the roof membrane was already not in the best state. Now there is few holes and during last winter, when the wind was quite strong, it was blew a bit of snow here and there. 

Now I know the proper way would be to remove the tiles and replace the whole membrane, but I doubt i will be able to afford it at the moment.

Could you please let me know:
- what cost do I face to do it properly inc the scaffolding (it's a semi detached, 2 storey house)
- do I need the membrane at all
- could I possibly "replace/fix" the membrane from inside, so cut it to smaller bits and attach in between rafters, to the side of the rafter using tape etc.

Thanks in advance
Peter

[Cpd]

21 minutes ago, wooju said:

what cost do I face to do it properly inc the scaffolding (it's a semi detached, 2 storey house)
- do I need the membrane at all
- could I possibly "replace/fix" the membrane from inside, so cut it to smaller bits and attach in between rafters, to the side of the rafter using tape etc.

1. Impossible to know without more detail. Size of building, ease of location for scaffolding, condition of existing tiles and other parts of roof like flashings. There are a number of diffrent roofing membranes that may or may not work depending on the roof makeup. Search forum for more info. 

2. Yes you need a membrane as it’s there as a secondary protection layer for things like “snow blowing in” and and leaks due to tile damage. 

3. I would say NO it’s not possible to fix from the inside, yes you could possibly do an emergency repair to a known location but beyond that would be a waste of time and money. 

 

Some photos of the roof from inside and outside would help to visualise what the problem is and if it can be fixed without a full re-roof. 

 

[nod]

1 hour ago, wooju said:

Hello all, 
I bought a house few years ago and the roof membrane was already not in the best state. Now there is few holes and during last winter, when the wind was quite strong, it was blew a bit of snow here and there. 

Now I know the proper way would be to remove the tiles and replace the whole membrane, but I doubt i will be able to afford it at the moment.

Could you please let me know:
- what cost do I face to do it properly inc the scaffolding (it's a semi detached, 2 storey house)
- do I need the membrane at all
- could I possibly "replace/fix" the membrane from inside, so cut it to smaller bits and attach in between rafters, to the side of the rafter using tape etc.

Thanks in advance
Peter

 Nowadays roof membranes are breathable So they are not waterproof like the old felt was If the tiles are not letting water in I would leave well alone 

and perhaps look towards re roofing in a few years time

[Jeremy Harris]

5 minutes ago, nod said:

 Nowadays roof membranes are breathable So they are not waterproof like the old felt was If the tiles are not letting water in I would leave well alone 

and perhaps look towards re roofing in a few years time

 

 

Just by way of clarification, modern roofing membranes are 100% water proof, but they are vapour permeable.  The technology is very similar to that first developed by Gore-Tex, for their first rate waterproof clothing, but there are now dozens of variations on a similar theme.

 

A modern membrane will keep water out every bit as effectively as something like sarking felt, but has the benefit that it allows water vapour (the gaseous form of water) to permeate through so reducing the risk of condensation forming.

[nod]

3 hours ago, JSHarris said:

 

 

Just by way of clarification, modern roofing membranes are 100% water proof, but they are vapour permeable.  The technology is very similar to that first developed by Gore-Tex, for their first rate waterproof clothing, but there are now dozens of variations on a similar theme.

 

A modern membrane will keep water out every bit as effectively as something like sarking felt, but has the benefit that it allows water vapour (the gaseous form of water) to permeate through so reducing the risk of condensation forming.

I was trying to point out difference between old an new

Old would waterproof a roof 

It’s not unusual to find lines of drips off a newly membrane roof that has no skates or tiles 

Wet to the touch 

[Declan52]

How big are the holes?? A few pics would help.

I repaired mine from the inside in my last house. I cut a thin slice horizontal just above the hole. Put a long rectangle shape piece of membrane down through the slit and pulled it down so it covered the hole on the outside with a flap sticking through the slit on the inside.

Used some silicone and glued the flap on the inside and the 3 sides of the underneath of the rectangle to the existing felt. Then cut a patch and glued in on from the inside over the hole.

It was not a handy job at all to do and it was between the battens so was easier to do as above.

[Jeremy Harris]

29 minutes ago, nod said:

I was trying to point out difference between old an new

Old would waterproof a roof 

It’s not unusual to find lines of drips off a newly membrane roof that has no skates or tiles 

Wet to the touch 

 

 

 Remember that really wet and windy Christmas period in 2013, with all the flooding?  Our new house just had membrane on the roof for around 8 weeks, as the weather was too bad for the roofers to get up there.  Not a drop of water came in, anywhere. 

[Cpd]

I had a bad experience with roof shield, it’s used all over this part of Scotland and I was led to believe it was a better product than some others I was looking at.

However there is a situation where if the exposed membrane gets really wet and then it freezes it no better than a bucket with a hole in........ the frozen water must do irreparable damage to the structure of the fabric because when it melts the water ingress is huge and it nearly ruined the sheeting on my shed roof. I would not use it again if these conditions were possible. Other times I have used it in summer and it works great at keeping the rain out. Not sure if this would be the same for other membranes of the same type. 

[Jeremy Harris]

The stuff on our roof was great, kept really heavy rain out for weeks.  IIRC it was Ampack Ampatop  Aero: http://www.ampack.eu/eu/products/membranes/roof-membranes/products/ampatop-aero-15-m/

 

Quote from that site:

 

Quote

Triple-layer, extremely tear-proof PP fleece with coating. Wind-proof, and can be taped securely against rain; highly permeable to vapour. Available in widths of 1,5 m and 2,8 m, with and without integrated tape.

 

• Printed-on cutting and orientation aid
• Withstands driving rain and is windtight
• Anti-slip on both sides
• Vapour open

 

Ours had the integrated tape, so all the overlaps are sealed securely with a self-adhesive band around 150mm or so wide at the lower edge  of each horizontal run.

[ProDave]

If you are looking for a recommendation, we have Protect VP400, chosen by the builder as it can be left exposed for a long time.

 

It was close on a year before the roof git tiled, and the walls of our sun room are still clad in this (with no outer covering) 3 years later with no problems.

[wooju]

Thanks everyone for all you replies and comments. I attach a photo of the worst bit but have few more smaller holes here and there
I don't think I can patch any of the holes due to the fact the remaining membrane is quite dry and crumbles when touched. 
In regards to the size of the roof, I will try to calculate it all tomorrow. For now, I would say it is an ‘average’ size and that the house is in Essex. 
Why cutting the roll of membrane in to few rectangular pieces and sticking it to timber is not ideal? Is it because I lave some exposed pieces of timber?